Robust event-triggered finite-time control of faulty networked flexible manipulator under external disturbance

Abstract

In this paper, finite-time contractive stability analysis and observer-based H _∞ fault tolerant control problem is discussed for a networked single-link flexible manipulator subject to external disturbance, actuator, and sensor faults. The variable delay is considered in both sensor-to-controller and controller-to-actuator channels. In order to conserve the network resources and avoid Zeno phenomenon, the sampled-data-based event-triggered scheme is employed, which only requires the system states in discrete instants. The nonlinear unknown input observer is first designed to achieve the estimation of the system states and faults simultaneously. To reduce the conservatism of designing procedure, the Lyapunov–Krasovskii functional approach is used, which includes the information of the lower and upper bounds of variable data transmission delay. Then, sufficient delay dependent conditions are derived and an observer-based feedback control law and observer gains are computed by a set of linear matrix inequalities to realize that the augmented system is finite-time contractive stable and the states of the system remain within a specified threshold during a fixed time interval, which is smaller than the initial state bound. Furthermore, the prescribed H _∞ performance is satisfied in the presence of external disturbance. At last, simulation results are given to confirm the validity of the presented approach.